Due to the seasonal and impulse-purchase nature of many products, sale facilities can go from fully stocked to out-of-stock on key promotional items very quickly. In many such cases, additional stock can be pulled from proximal storage areas to rapidly remedy situations if alerts can be generated to indicate that stocked product volume is waning or fully depleted. In other cases, early notification of partial or full out-of-stock conditions significantly decreases the period where sales are lost due to lack of merchandise. In the case of temporary or permanent displays, low- or no-stock conditions can result in the display being pulled from the selling area, and in many cases, destroyed or discarded.
Many Consumer Packaged Goods (CPG) items have such erratic sales patterns. For example, an entire section of soda or bottled water can be depleted from supermarket shelves in a few hours. Often there is no safety stock in the back room, and it can take a significant amount of time for store personnel to notice that the shelf is depleted and place a replenishment order. Substantial sales increases often occur when product is displayed, featured, or given a significant price reduction for a certain period. Out-of-stock conditions result in missed sales and frustrated customers.
Trade publications forecast widespread use of RFID tags on consumer products to complement the UPC (i.e. ePC) in a 5–15 year timeframe. However, such system is subject to the future development of a very inexpensive tag, cheaper and more effective readers, and full deployment of shelf-based antenna systems in retail outlets. Thus, sophisticated, inexpensive systems predicated on such use of the ePC (passive RFID tags applied to individual product items) are years away from being implemented.
Further, temporary displays are often discarded after only a few days or weeks, which means that stock-status detection equipment would need to be either disposable or very portable and easily redeployed by non-technical in-store personnel. When implemented, such systems may not cover certain types of product or packaging due to their challenging RF properties.
In applicant's commonly assigned and published application S.N. US 2004/0056091, incorporated herein in its entirety, there is disclosed RF tags of various types (e.g. passive, semi-passive, active, and the like), Backscatter Reader Transmitters (BRT), and hubs. Typically, each BRT is a fully self-contained, battery operated unit, and utilizes three antennas. Two medium gain patch antennas are used to read the tags, and a whip antenna is used to report the received data over a wireless link to the hub. Active transmitter tags can have contacts or other sensors that allow them to function like “readers” by collecting data proximal to them and reporting directly to the hub.
It would be advantageous to modify such system for detecting and monitoring presence/absence of stocked product in a simple, economical manner. What is desired, therefore, is a simple, inexpensive device that can detect and report on-shelf product status as being out-of-stock, fully stocked, or some state in between, regardless of where the items are displayed in the store or facility.